1. Field of the Invention
The present invention relates to a method for color image formation and to a silver halide photosensitive material used for the method. More particularly, the invention relates to a method for forming a color image which has a high speed and a superior storability and which further has a superior color image storability, and to a silver halide photosensitive material which can yield such color images.
2. Description of the Related Art
In the field of silver halide color photosensitive materials, to enhance speed without deterioration in graininess is a long-existing problem. The photographic speed generally depends on the size of silver halide emulsion grains. The larger the emulsion grains, the more the speed increases. However, since the graininess deteriorates with increase of the size of silver halide grains, the speed and the graininess have a trade-off relationship. In this field, to increase the speed without deteriorating the graininess is the most basic and important problem in improving the image quality of a photosensitive material.
A technique of increasing the speed without deteriorating the graininess by incorporating, in a silver halide photosensitive material, a compound having at least three hetero atoms, has been disclosed, for example, in Jpn. Pat Appln. KOKAI Publication No. (hereinafter referred to as JP-A-) 2000-194085 and JP-A-2003-156823.
However, although the speed is increased by the above-mentioned method, the effect thereof is insufficient, and the use of the method has caused some new problems. It has been found that the photosensitive materials obtained by use of the method have deteriorated raw photosensitive material storability.